The present case report describes a 19-year-old male patient whose main symptoms were emotional coldness, absence of close relationships, difficulty experiencing pleasure with other people, and lack of motivation to work or to continue his studies. A schizoid personality disorder was diagnosed as a product of early maladaptive patterns such as inhibition, emotional deprivation, social isolation, and inadequacy. Likewise, a rigid and fragmented family context was evidenced, with an affective absence of parents and a focus on strict behavioral rules. The study aimed to intervene, from a cognitive clinical approach, the early maladaptive patterns and symptoms that maintained the features of schizoid personality disorder in the patient. For this purpose, cognitive behavioral therapy was carried out, with techniques such as debates, images to reparentalize, assignment of tasks, use of humor, and social skills training, among others. In conclusion, it can be stated that the early maladaptive patterns maintained the schizoid personality symptomatology. Finally, it was demonstrated through clinical and psychometric criteria that cognitive behavioral therapy decreased schizoid personality behaviors in the patient.